1. Field of the Invention
The present invention relates to a self-service checkout system, and more particularly, to improvements to conveyors, weighing mechanisms and delivery area devices used with such systems.
2. The Prior Art
Self-service has benefited consumers and retailers alike. Such systems have been widely adapted for purchasing gasoline at self-service service stations and are now becoming more available in retail stores.
Self-service checkout systems currently on the market included conveyor systems for the automated checkout of articles selected by a customer for purchase in supermarkets and like facilities. Articles for purchase generally bear a so-called “universal product code” (UPC), typically in the form of a bar code uniquely indicative of the identity of the article bearing the code. The UPC of each article selected for purchase is scanned using a bar code scanner or read and a signal indicative of the article identity is generated and applied to a central processing unit (CPU) which has stored in associated memory storage for the UPCs of all articles available for purchase which are so encoded, correlated with the price and other characteristics of the articles, such as weight.
Articles are placed on a conveyor following UPC for transportation to a packaging area. When the article is placed on the conveyor, a scaling device incorporated with the conveyor system weighs the item. The weight obtained from the conveyor measurement is compared to a weight of the product from the database. If the weight from the conveyor is within a predetermined tolerance of the weight from the database, then the article is allowed to continue down the conveyor to a second transport conveyor where it is deposited in a collecting area. If the weights are different (taking into consideration the tolerances), then the security conveyor is reversed and the article is returned to be re-scanned and re-weighed.
One of the problems of conveyor belt weighing systems is that of accuracy. The movement of the belt, its tracking, as well as potential movement of a motor driving the conveyor each and collectively increase the inaccuracies of the weighing mechanisms. These problems are amplified by the unique backward and forward movement of the conveyor in a self service checkout devise that has security return features. Additionally these inaccuracies cause false rejection of articles, resulting in the requirement of supervisory personnel having to be present to enable the self-checkout lane to pass the article through the security zone.
This is especially a problem for light weight articles, where the tolerances used (as a result of the inaccuracies of the conveyor system weighing mechanism) are greater than that of a light-weight product. This tolerance is amplified since the weighing mechanism tolerances are incorporated into the database for each item checked against the item database. The tolerance is applied to a zero value and declared as a starting point prior to scanning in any item, for any measurement taken.
Another problem facing conveyor type self-checkout systems is utilization of the entire packaging area. Currently, as articles come off the end of the conveyor system, they encounter an incline on their way to a packaging (i.e., bagging) area. The incline imparts a frictional drag on the bottom surface. As a result, the friction stops the articles on the incline, causing the articles to back up on the incline. This ultimately jams up the end of the conveyor, and the packaging area is not utilized.
The above stated problems all result in slower purchasing and throughput times, lowering the sales volume for store owners and requiring shoppers to spend more time waiting in line.